a. Field of the Invention
The present invention relates to sheaths or introducers. More particularly, the present invention relates to a steerable short sheath access device or introducer for use in epicardial procedures, such as those used for the treatment of atrial fibrillation and ventricular tachycardias.
b. Background Art
Many medical procedures require the introduction of specialized medical devices into and/or around the human heart. In particular, there are a number of medical procedures that requires the introduction of specialized devices, including but not limited to catheters, dilators, and needles, to areas such as into the pericardial sac surrounding the heart in order to access the epicardial or outer surface of the heart. Catheters and access sheaths or introducers have been used for medical procedures for a number of years. It is necessary for introducers and catheters to exhibit a degree of flexibility to be able to maneuver through the vasculature of a patient during the performance of cardiac procedures. In addition, various configurations of introducers are necessary for the treatment of different cardiac conditions.
Atrial fibrillation and ventricular tachycardias are cardiac arrhythmias that result in an irregular heartbeat due to the irregular conduction of electrical impulses to the ventricles of the heart. It is believed that one method of treating atrial fibrillation is through the locating, accessing, stimulating, and ablation of epicardial neuroganglia. It is believed that atrial fibrillation can be controlled more completely by ablating neuroganglia heads located under (or inside) fat pads located on the epicardial surface of the heart. The fat pads are located at the junctions of the pulmonary veins, the inferior vena cava, and in the margin between the aorta and the superior vena cava, all of which may in fact be a major source of fibrillation. Current treatments that involve ablating alternate pathways internal to the heart may be ineffective in truly reaching neuroganlia and instead targets the legs of the neuroganglia, which can necessitate multiple ablations. As a result it is desirable to develop a method of targeting the neuroganlia heads so that the entire circuit can be resolved by ablating the head embedded in or below the fat pad.
In order to ablate the head of the fat pad located on the epicardial surface, it is necessary to use an ablation catheter that is able to access the epicardial surface of the heart. Traditional approaches to treating atrial fibrillation include the use of introducers or catheter systems that are inserted within the internal chambers of the heart to target areas for ablation. Traditional catheters and access devices, such as introducers, access these endocardial areas through a rigid elongated body that includes a curved portion for accessing areas of the heart and related vasculature for ablation. These traditional catheters and access devices can be too long in length to be used in certain pericardial procedures such as that for potential treatment of atrial fibrillation. Moreover, these traditional devices are not able to be maneuvered or steered to reach the epicardial surfaces for treatment or they may have to be curved throughout the pericardial sac and around the heart to reach the tissue areas of interest.